Hardware trigger for bookmarks

IP I/O is great an all but expensive and complicated.
Soft triggers are awesome but not everyone has a guard in front of the computer.

I'm sure you guys develop with raspberrypi, this seems like a simple way to interact with the API

One usecase is at my local deli. As you can imagine they have a lot of problems with shop lifting. The guy there has an awesome memory because he can recall events and the time almost to the minute and I help him out looking through the DVR sometimes. But software is better. Something like a "panic" button that could be mounted under the counter that could trigger a bookmark at that time (or length of time based on how many times button was pressed) so that anyone else like the owner could quickly review the footage later on or remotely.

I have a raspberry pi zero, some buttons, and a 3D printer. I was thinking to make a python script that would send out that API request. However I'm not much of a developer. Was wondering if you guys played around with the idea for some rapid custom I/O based on the raspberry pi.